Technical Service Bulletin
Technical Service Bulletins, or TSBs, are recommended procedures for repairing vehicles. They are a form of diagnosis. Not to be confused with recalls, a TSB is issued by a vehicle manufacturer when there are several occurrences of an unanticipated problem. TSBs can range from vehicle-specific to covering entire product lines and break down the specified repair into a step-by-step process. While sometimes written by engineers employed by OEMs, the majority are authored by the first automotive technician to come up with a repair procedure. Because certain problems may have more than one cause and there is sometimes more than one way to fix a problem, it's somewhat common for there to be more than one TSB for the same problem.
One major difference between a recall and a TSB in the automotive industry is that a recall usually evolves out of safety issues at the behest of an organization like the National Highway Traffic Safety Administration (NHTSA). The ensuing recall maintenance/repair work is usually done at no charge to the car owner, regardless of the car's warranty status. Dealers are usually under no mandate to call in cars for which there are TSBs to do the related repairs. Nor is there an obligation to do the TSB repairs for free or at reduced charges to the owner, since the manufacture does not require the repair to be performed and does not reimburse the dealership for repairs. When the vehicle's manufacturer releases a recall, they not only require the dealership to perform the repair, but will reimburse them the recall's repair.
Some benefits of an automotive TSB are that by widely circulating among dealership service departments and mechanics an engineering-level description and solution for a problem common to type, year, make or model of car, a well-managed TSB process can save technicians troubleshooting time; provide organized, itemized repair procedures; and standardize the repair process. This can also enhance the quality of the maintenance since it tends to be supported by repair history and high-level diagnostic procedure decisions.
NPR's Car Talk show duo, Tom Magliozzi and brother Ray Magliozzi (also known as "Click and Clack"), describe TSBs, saying, "They really just contain advice from the company to the mechanics who fix their cars," in this S.F. Chronicle article, "Technical Service Bulletins Explained." But this Edmunds article, "How Can a Technical Service Bulletin Help Me?" states that if there is a TSB for your particular problem, and it's verifiable by the dealer, then the repair is free to cars within the warranty period.